I'm a flatlander also with the 900 switchback if you run the 11 series weights it will hold you clutch out farther you need to ask indy dan what weights he use to shim your clutch and stay with them or the shimming will be off.same with the belt use the same as it was shimmed for. I use the black/green on primary and the 720 helix but what ever you use check out the weights they will change the way the clutch is shimmed. I've tried it.Ok, and what about primary? I am thinking of trying stock first with the 11 series weights. Should I reconsider that also?